Chapter 4: Web management
136
NS3550-8T-2S Industrial Managed Switch User Manual
Buttons
• Click
Refresh
to refresh the table starting from the
Start from VLAN
and
entries
per page
input fields.
• Click
I<<
to update the table starting from the first entry in the VLAN table (i.e., the
entry with the lowest VLAN ID).
• Click
>>
to updates the table, starting with the entry after the last entry currently
displayed.
• Click
Save
to save changes.
• Click
Reset
to undo any changes made locally and revert to previously saved
values.
IGMP snooping port group filtering
In certain switch applications, the administrator may want to control the multicast
services that are available to end users (an IP/TV service based on a specific
subscription plan, for example). The IGMP filtering feature fulfills this requirement by
restricting access to specified multicast services on a switch port, and IGMP throttling
limits the number of simultaneous multicast groups a port can join.
The IGMP Snooping Port Group Filtering Configuration page permits assigning a profile
to a switch port that specifies multicast groups that are permitted or denied on the port.
An IGMP filter profile can contain one or more, or a range of, multicast addresses.
However, only one profile can be assigned to a port. When enabled, IGMP join reports
received on the port are checked against the filter profile. If a requested multicast group
is permitted, the IGMP join report is forwarded as normal. If a requested multicast group
is denied, the IGMP join report is dropped.
IGMP throttling sets a maximum number of multicast groups that a port can join at the
same time. When the maximum number of groups is reached on a port, the switch can
take one of two actions; either “deny” or “replace.” If the action is set to deny, any new
IGMP join reports will be dropped. If the action is set to replace, the switch randomly
removes an existing group and replaces it with the new multicast group.
